Impact of Sedimentation on Water Seepage Capacity in Lake Nakuru, Kenya

Parfait Iradukunda,Maurice O Nyadawa,Fedor Lisetskii

doi:10.1155/2021/8889189

Abstract

Accumulation and deposition of sediments in waterbody affect the seepage capacity that could lead to improper water balance and results in the water level rise. This study analysed the influence of sedimentation on seepage capacity in Lake Nakuru and the impact of sediment characteristics to the water seepage and the flow rate formation at the lake bed level. The study was performed by sampling and analysing the sediment cores from two locations in the lake. The sediment hydraulic properties, i.e., moisture and porosity, particle sizes, and hydraulic conductivity, were determined using the oven-drying method, sieve analysis, hydrometer analysis, and falling head tests, respectively. The results showed that the lake sediment sample from location P1 had an average ratio of 39.38% for silty soil, 34.00% for clayey sediment, and 26.63% for fine-sand sediment particles with the maximum permeability coefficient of 3.37 ∗ 10 − 5 cm/s, while the one from location P2 had an average ratio of 63.17% for sand, 20.17% for fine particles, and 16.67% for gravels with the maximum permeability coefficient of 0.010793 cm/s. The hydraulic conductivity of sediment sample from location P1 and P2 increased along the core depth. This could lead to the rise of water level due to the decreases of water movement induced from the sediment cementation in the top layers under the waterbody. Sedimentation affects Lake Nakuru water volume and water balance; hence, there is a need to control the inflow of sediment resulting from anthropogenic activities in the watershed.

Highlights

Sedimentation is a major environmental threat to sustainability and related water resource efficiencies [1]
It was observed that water content at the top of the core was found to be more than 800%. is can be attributed to high presence of fine particles at the top of sediment core
Conclusions and Recommendations e sediment core from location P1 had more than 800% water content at the top which decreased along the core with bottom of sediment core having about 300% water content

Summary

Introduction

Sedimentation is a major environmental threat to sustainability and related water resource efficiencies [1]. Accumulation and deposition of sediment in the lakes and reservoir is a concerning factor threatens their functionality [2,3,4]. It has been recognized as a major problem in the lakes and the use of surface water supplies [5]. E different hydraulic properties of deposited sediment affect water level and the lake water balance through their ability to allow or prevent the water seepage in the Rift Valley lakes [7]. E major surface water discharge into Lake Nakuru include several rivers, spring perennial rainfall, sewage plant effluent, and groundwater recharge [13, 14]. River Njoro is the main source of the sediment delivered in Lake Nakuru with 70%, followed by Makalia

Methods

Results

Conclusion